Recs.
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Spotify is a freemium music and podcast streaming service with a library of over 30 million songs and clients for a wide array of platforms, including Windows, MacOS, Linux, Android, and iOS, as well as a web player.
SpecsUpdate
Pros
Pro Huge collection of music and fast access to newly released songs
Spotify has over 20 million songs and arguably the largest collection out of its competitors and usually has the fastest access to new music.
The Spotify desktop client allows local music files to be imported with the option of syncing with a mobile device which largely mitigates the issue of missing artists.
Pro Client's functionality can be extended via third-party apps
Spotify desktop client allows for third-party apps. They extend the functionality of Spotify and many of them offer new ways of discovering music. Noteworthy apps include Moodagent, Last.fm, Swarm.fm, ShareMyPlaylists, The Hype Machine, We Are Hunted, Shuffler.fm.